Improved error-table compensation of A/D converters

Previous work has shown that phase-plane and state-space error tables can be used to improve the linearity of analogue-to-digital converters. The calibration signals used to generate the error table were incremented amplitude sinusoids, leaving unfilled regions in the table that correspond to the high input signal frequencies and amplitude levels, and usually highest error. The paper proposes the use of more elaborate calibration signals for generating the error tables. It is shown that the use of pseudorandom calibration signals leads to superior error-table coverage and improved compensation over the frequency range of interest. The error-table compensation method is briefly compared with an alternative technique based on the Volterra inverse.